Photographh by Jon Bradley

Steve Shiel, 46, is scientific director, UK and Ireland, at cosmetics giant L’Oréal. After a BSc in chemistry at Swansea University and a PhD in organic chemistry at the University of Birmingham, he worked for 20 years in the cosmetics business of Procter & Gamble before joining L’Oréal in August 2015.

When I was six we did a school experiment replicating a volcano in action, and I was hooked. I begged for a chemistry set and built my own laboratory in the shed, and that delight in discovery and exploration and finding out how things worked has never left me.

I began my scientific career in nappies as an intern at Procter & Gamble. Believe it or not nappies are all about materials science. They need to be absorbent, allow the transfer of liquids while remaining dry on the surface, and be flexible and robust at a range of temperatures. Pampers are a lot more complex than people think.

The amount of science in shampoo is amazing. It may have 20 or 30 ingredients that control not just how it cleans but how much lather it produces, how fast it rinses off and how we get active compounds such as anti-dandruff treatments to stick to the scalp.

We learn from many sources. The clothing industry uses positively charged cationic polymers to condition fabrics. Damaged hair tends to become negatively charged, so these positively charged polymers are attracted to the parts of the hair that need them most. And we’ve developed Filloxane, a chemical to increase the volume and fullness of hair, that was inspired by technology to fix cracks in car windscreens.

My hair has been every colour from jet black to blond with strange hints of green and blue. Mixing hair dyes is a bit like alchemy and we don’t always get it quite right first time. Research scientists often try out cosmetics products on themselves; you’ll see men wandering round the lab wearing foundation make-up, and my bathroom has always been like a small branch of Boots.

Science is fundamental to L’Oréal. The company was founded by a scientist and spends 4 per cent of its revenue on scientific research – that’s €760 million each year. It couldn’t function without cutting-edge science and innovation.

Dermatologists are often amazed at the scientific rigour that goes into cosmetics, such as double-blind, placebo-controlled clinical testing. L’Oréal employs more than 3,700 scientists who take out patents, attend conferences and publish papers in peer-reviewed journals. Often we lead the way in research into healthy hair and skin (medical research is usually more concerned with diseased tissue) so there’s a dialogue of equals between the two professions.

One of the fun parts of my job is explaining the “science within the bottle” to a huge range of audiences, from dermatologists to hairstylists to consumers. For the latter I always ask myself how I’d explain it to my mother.

Don’t dismiss cosmetics as frivolous. They have a huge impact on how people feel about themselves and interact with others, and one thing that fascinates me is the crossover between fundamental sciences such as chemistry and biology and the psychology of this human impact. There’s an enormous amount of scientific discovery still to be done in cosmetics, and it’s directly applicable to practical things that touch people’s lives every day.